When the Professional Bull Riders tour stops in Cowboys Stadium this weekend, two rivals will go head-to-head.And we’re not talking cowboys. We’re talking bulls.A bovine named Asteroid, who is the defending world champion, and Bushwacker, who won the 2011 world title, are scheduled to perform during the final round on Saturday night.Judges will score each bull. It’s the first time this season that each bovine has been on the card at the same show.Kent Cox of Dublin, who manages Bushwacker for Julio Moreno Bucking Bulls, said the bovine is performing exceptionally well.“He’s in the prime of his life and he’s showing it, ” Cox said of 7-year-old Bushwacker, who is 3-0 this year against the cowboys.Bushwacker has bucked off world title race leader Shane Proctor (in 2.48 seconds), Luke Synder (1.98) and Mike Lee (3.31).After ousting Lee last weekend in Kansas City, Mo., Bushwacker fell just two points shy of a perfect score with a 48.Asteroid, owned by Circle T Ranch & Rodeo, is also 3-0 in 2013. He has disqualified Eduardo Aparecido (1.21 seconds), Lee (3.4 seconds) and Guilherme Marchi (4.86 seconds).The Arlington show, called the Dickies Iron Cowboy IV, is a bracket-style, tournament competition featuring 24 riders. The winner will receive $50,000 and the opportunity to pocket another $50K if he can conquer the show’s bonus bull, Monster Energy Money Bull Shepherd Hills Tested of Luthy/Duckwall/D&H Cattle/Shepherd Hills Cutlery. Shepherd Hills Tested is 4-0 this season.Ticket prices range from $20 to $150. A concert by country music star Kevin Fowler begins at 7 p.m. and the Ford Series show starts at 8.Tickets are available on Ticketmaster.com or by calling 800-745-3000. Fans also can learn more by visiting pbr.com.Another BrazileThere’s a new San Antonio Stock Show Rodeo champion in the Brazile family.Trevor Brazile, the 10-time world all-around champion, has earned prestigious titles at the Alamo City’s famous rodeo over the years. But last weekend, the spotlight shifted to his wife, Shada, who clinched the barrel racing championship and earned $16,866.She was the first barrel racer to compete and set the pace at 13.93 seconds aboard her horse, Dial It Fast, whom she calls “Big Boy.”“I couldn’t believe it,” Shada Brazile said. “Praise God for a great horse.”E.J. Roberts of Stephenville clinched the tie-down roping title and Plano’s Drew Horner finished No. 1 in team roping heading.One hot roperRandall Carlisle, a former Lipan resident who lives in College Station, won the Tucson (Ariz.) Rodeo’s $7,181 tie-down roping title last weekend. Two weeks ago, he won the Fort Worth Stock Show Rodeo. Carlisle is ranked fourth in the Professional Rodeo Cowboys Association’s tie-down roping world title standings with $19,689.